1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Part 1: Determination of essential image quality parametersThe European Standard EN 62464-1:2007 ha
2、s the status of a British StandardICS 11.040.50Magnetic resonance equipment for medical imaging BRITISH STANDARDBS EN 62464-1:2007BS EN 62464-1:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2007 BSI 2007ISBN 978 0 580 53390 7Ame
3、ndments issued since publicationAmd. No. Date CommentsThis publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis Brit
4、ish Standard is the UK implementation of EN 62464-1:2007. It is identical to IEC 62464-1:2007.The UK participation in its preparation was entrusted by Technical Committee CH/62, Electromedical equipment in medical practice, to Subcommittee CH/62/2, Diagnostic imaging equipment.A list of organization
5、s represented on this committee can be obtained on request to its secretary.EUROPEAN STANDARD EN 62464-1 NORME EUROPENNE EUROPISCHE NORM May 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische N
6、ormung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 62464-1:2007 E ICS 11.040.50 English version Magnetic resonance equipment for medical imaging - Part 1: Determi
7、nation of essential image quality parameters (IEC 62464-1:2007) Appareils rsonance magntique pour imagerie mdicale - Partie 1: Dtermination des principaux paramtres de qualit dimage (CEI 62464-1:2007) Magnetresonanzgerte fr die medizinische Bildgebung - Teil 1: Bestimmung der wesentlichen Bildqualit
8、tsparameter (IEC 62464-1:2007) This European Standard was approved by CENELEC on 2007-04-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-
9、date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation und
10、er the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Fra
11、nce, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 62464-1:2007 Foreword The text of document 62B/641/FDIS, future edition 1 of IEC
12、 62464-1, prepared by SC 62B, Diagnostic imaging equipment, of IEC TC 62, Electrical equipment in medical practice, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 62464-1 on 2007-04-01. The following dates were fixed: latest date by which the EN has to be implemente
13、d at national level by publication of an identical national standard or by endorsement (dop) 2008-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-04-01 In this standard, the following print types are used: requirements, compliance with which
14、can be tested, and definitions: roman type; explanations, advice, notes, general statements and exceptions: smaller roman type; test specifications: italic type; terms defined in Clause 3 of EN 60601-1:2006, in this standard or in IEC/TR 60788: SMALL CAPITALS. Annex ZA has been added by CENELEC. _ E
15、ndorsement notice The text of the International Standard IEC 62464-1:2007 was approved by CENELEC as a European Standard without any modification. _ 2 CONTENTS INTRODUCTION 5 1 Scope 6 2 Normative references 7 3 Terms, definitions and symbols . 7 3.1 Terms and definitions . 7 3.2 Symbols 11 4 Proced
16、ures for the determination of essential image parameters 17 4.1 General requirements for all procedures17 4.2 SIGNAL TO NOISE RATIO .18 4.3 UNIFORMITY21 4.4 SLICE THICKNESS in 2-D scanning .24 4.5 Two-dimensional GEOMETRIC DISTORTION29 4.6 SPATIAL RESOLUTION.33 4.7 GHOSTING ARTEFACTS .36 5 CONSTANCY
17、 TEST.39 5.1 Objectives and rational39 5.2 Requirements for the TEST DEVICE40 5.3 Scan characteristics 40 5.4 Measurement procedure40 5.5 Data analysis, reporting of results and tolerances .41 Annex A (normative) Alternative methods 42 Annex B (informative) Rationales 56 Bibliography. 75 Index of de
18、fined terms . 77 Figure 1 Insertion of a homogenous TEST DEVICE into the RF COIL 22 Figure 2 Position of the TEST DEVICE on the surface coil .22 Figure 3 Signal intensity profile in the inclined slab method .25 Figure 4 Correcting for rotation of TEST DEVICE .27 Figure 5 TEST DEVICE example for a sp
19、herical SPECIFICATION VOLUME, consisting of a polypropylene carboy (Perspex) cylinder whose internal wall defines the ROI perimeter 30 Figure 6 TEST DEVICE example for a spherical SPECIFICATION VOLUME, consisting of a number of vials distributed on the ROI perimeter30 Figure 7 Two lines passing thro
20、ugh the centre of the TEST DEVICE 31 Figure 8 Distances to be determined32 Figure 9 Periodic pattern34 Figure 10 Image of periodic pattern and position of ROI.35 EN 62464-1:2007 3 Annex ZA (normative) Normative references to international publications with their corresponding European publications 7
21、9 Figure 11 TEST DEVICE (circular object), ghosts (crescents), and REGION OF INTEREST (ROI) measurement boxes for mean signal, ghost, and noise measurements 38 Figure A.1 Wedge TEST DEVICE.47 Figure A.2 Measurement of SLICE PROFILE and SLICE THICKNESS using wedge TEST DEVICE 48 Figure B.1 Relaxation
22、 times T1and T2in dependency on the concentration of CuSO4 5 H20 58 Figure B.2 Centring error 68 Table B.1 TEST DEVICE conductivity and dielectric properties. 60 Table B.2 Comparison of company bandwidths . 64 Table B.3 Relaxation fit parameters for GdTMHD concentrations 4 parts per thousand by weig
23、ht 65 EN 62464-1:2007 4 INTRODUCTION This international standard is written at a moment in which MAGNETIC RESONANCE EQUIPMENT is already present in the market place for more than 20 years. It is estimated that more then 20 000 scanners are operational and more than 0,5 billion PATIENTS have been sca
24、nned. A number of standards on quality assurance and quality control have been developed by national committees to address the need for quantitative addressing of system performance and system maintenance. It is therefore felt to be necessary to introduce this IEC standard in addition to the existin
25、g standard on MAGNETIC RESONANCE (MR) safety, because the IEC standards have a true international character and this IEC standard is the first start to process and combine current best practices together and provide guidance on how to address the various questions on quality control and quality assu
26、rance testing of MAGNETIC RESONANCE EQUIPMENT together. Having a standardized set of test methods minimizes the amount of work for the MR MANUFACTURERS to demonstrate the performance characteristics of the MR scanners for many different countries and in addition, these countries do not have to formu
27、late their own requirements for the performance testing. Since MR scanners have been around for some time, this international standard is an attempt to consolidate the current way of working for the quality control of the performance characteristics concerning essential image quality parameters, and
28、 does not introduce major new development efforts for the established MR equipment to fulfil the requirements of this standard. This objective is achieved by introducing preferred methods in the main text of the standard, while allowing acceptable alternative test methods, described in Annex A of th
29、e standard. A number of the ACCEPTANCE TEST methods described in the standard have already been described earlier, mainly as NEMA technical MR standards, while new methods have been developed since then. For this standard, it is attempted to select the best method as the preferred method, although f
30、or a number of specific tests good alternatives are available and are therefore also acceptable. Also for the quality assurance tests and the CONSTANCY TESTS, each MANUFACTURER has developed its own test device and related test procedures and data analysis in the past years. For the CONSTANCY TESTS
31、it was therefore decided not to describe detailed test methods but only prescribe the parameters to be measured and essential conditions for these measurements in the main standard. This provides the necessary latitude to account for the many unique MR designs (extremity scanners, whole body scanner
32、s, cylindrical versus open scanners, various field strengths, phantom design, data analysis) and examples for possible CONSTANCY TESTS for the required parameters in the annex. This allows the user to use as many of the tools supplied by MR MANUFACTURERS as possible, appropriate and useful and still
33、 fulfill the requirements for quality control and quality assurance. EN 62464-1:2007 5 MAGNETIC RESONANCE EQUIPMENT FOR MEDICAL IMAGING Part 1: Determination of essential image quality parameters 1 Scope This international standard specifies measurement procedures for the determination of many essen
34、tial medical MR EQUIPMENT image quality parameters. Measurement procedures as addressed in this standard are suitable for: - quality assessment in the ACCEPTANCE TEST; - quality assurance in the CONSTANCY TEST. In addition, the measurement procedures specified in this standard may also be useful for
35、 type tests, although that is not an objective of this standard. This standard does not address: - required levels of performance for ACCEPTANCE TEST and CONSTANCY TEST; - image quality assessment of high field MR EQUIPMENT greater than 4 T, if not otherwise stated; - image quality affected by MR-co
36、mpatibility issues; - special diagnostic procedures such as flow imaging, perfusion, diffusion, radiotherapy and image-guided therapy applications; - type tests. The scope of this standard is also limited to measuring image quality characteristics in TEST DEVICES, not in PATIENT images. The measurem
37、ent procedures specified in this standard are directed to: a) MANUFACTURERS, who can demonstrate compliance by performing acceptance and constancy methods as described by this standard, b) test houses, which can confirm performance of MR EQUIPMENT using methods described in this standard, c) regulat
38、ory authorities, who can reference this standard, and d) RESPONSIBLE ORGANISATIONS who want to perform ACCEPTANCE and CONSTANCY TESTS using methods described in this standard. The essential image quality parameters and measurement methodologies defined in this standard are: - SIGNAL-TO-NOISE RATIO,
39、- UNIFORMITY, - SLICE THICKNESS and SLICE PROFILE, - GEOMETRIC DISTORTION, - SPATIAL RESOLUTION, and - ghosting. EN 62464-1:2007 6 This standard describes the preferred measurement procedures. It also describes alternative methods in Annex A. The preferred test methods may be substituted with the al
40、ternative methods. If necessary, other methods not described in this standard may be used, provided these other test methods are documented and validated against the methods described in the standard. Validation of other test methods requires an analysis of test sensitivity to the same parameter of
41、interest and an analysis of the insensitivity of the test to other unrelated parameters and should demonstrate a similar, or better, level of sensitivity to the same parameter of interest and a similar, or better, level of robustness against unrelated parameters. All methods shall produce quantitati
42、ve results. The rationale to the preferred and alternate methods, and their pitfalls, are described in Annex B. This standard also presents requirements for CONSTANCY TESTS suitable for MR EQUIPMENT quality assurance programs concerning essential image quality parameters. There are no preferred CONS
43、TANCY TEST methods, to provide flexibility in using existing automated procedures where available, but suggested examples of test methods are found in Annex A. If necessary, other CONSTANCY TEST methods not described in this standard may be used. Since the needs of RESPONSIBLE ORGANISATIONS quality
44、assurance programs may vary, RESPONSIBLE ORGANISATIONS are encouraged to determine the necessary scope of tests, quality of the tests, and the sensitivity of the data analysis etc. This standard places an emphasis on consistently repeatable, automated measuring tools that facilitate trend analysis a
45、nd the frequent quick testing of a small set of important parameters which are sensitive to the overall operating characteristics of the MR EQUIPMENT. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edit
46、ion cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60788, Medical electrical equipment Glossary of defined terms 3 Terms, definitions and symbols 3.1 Terms and definitions For the purposes of this document, the following t
47、erms and definitions apply. 3.1.1 acceptance test test carried out after new EQUIPMENT has been installed, or major modifications have been made to existing EQUIPMENT, in order to verify compliance with contractual specifications IEC 61223-1, definition 3.2.4 EN 62464-1:2007 7 3.1.2 accompanying doc
48、ument document accompanying ME EQUIPMENT, an ME SYSTEM, EQUIPMENT or an ACCESSORY and containing information for the RESPONSIBLE ORGANIZATION or OPERATOR, particularly regarding BASIC SAFETY and ESSENTIAL PERFORMANCE IEC 60601-1:2005, definition 3.4 3.1.3 artefact apparent structure visible in the i
49、mage that does not represent a structure at the corresponding position within the object and that cannot be explained by noise 3.1.4 bandwidth per pixel reciprocal of the duration of the sampling window NOTE Instead of BANDWIDTH PER PIXEL, equivalent values may be stated on the control console. 3.1.5 body test device TEST DEVICE representing the PATIENTS body 3.1.6 constancy test each of a series of tests, carried out: to ensure that t
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